NASA scientist Rich Terrile has a neat way of explaining stuff that you or I should, by all rights, not be able to understand at all: he uses Grand Theft Auto IV as a means of explaining how we might all be living our lives in a giant galactic simulation.

Speaking with Vice, Terrile details how Liberty City can be a lot more than just a place to steal cars and buy bad coffee.

The natural world behaves exactly the same way as the environment of Grand Theft Auto IV. In the game, you can explore Liberty City seamlessly in phenomenal detail. I made a calculation of how big that city is, and it turns out it's a million times larger than my PlayStation 3. You see exactly what you need to see of Liberty City when you need to see it, abbreviating the entire game universe into the console. The universe behaves in the exact same way. In quantum mechanics, particles do not have a definite state unless they're being observed. Many theorists have spent a lot of time trying to figure out how you explain this. One explanation is that we're living within a simulation, seeing what we need to see when we need to see it.